Application: Architecture

Chapter 1: Introduction to RP for architectural studies
Chapter 2: Introduction to Fused Deposition Modeling (FDM)
Chapter 3: Introduction to StereoLithography Apparatus (SLA)
Chapter 4: Introduction to Selective Laser Sintering (SLS)
Chapter 5: Introduction to Laminated Object Manufacturing (LOM)
Chapter 6: Introduction to 3D Printing (Concept Modeling)
Chapter 7: Alternative use of rapid prototyping
Chapter 8: RPD equipment/material manufacturers around the World

Introduction to Fused Deposition Modeling (FDM)

The FDM process from Stratasys Inc. forms three-dimensional objects from CAD-generated solid or surface models. A temperature-controlled head extrudes thermoplastic material layer by layer. The designed object emerges as a solid three-dimensional part without the need for tooling.

FDM8000 (left) and FDM2000 (right).

The process begins with the design of a conceptual geometric model on a CAD workstation. The design is imported into a slicing software, which mathematically slices the conceptual model into horizontal layers. Another piece of software is used to generate the supports as required. The system operates in the X, Y and Z axes. In effect, it draws the model one layer at a time.

Thermoplastic modeling material in the form of filament, feeds into the temperature-controlled FDM extrusion head, where it is heated to a semi-liquid state. The head extrudes and deposits the material in thin layers of around 0.127mm onto a foam or acrylic sheet base (video). The head directs the material into place with precision. The material solidifies, laminating to the preceding layer.

The FDM nozzles.

Click here to read a detailed system overview of FDM

Advantages

• True desktop manufacturing system that can be run in office environment. There is no worry of exposure to toxic fume and chemicals.
• The process is clean, simple, easy to operate and produces no waste
• Fast building for bottle like structure or hollow parts
• Material is supplied in spool form which is easy to handle and can be changed in minute
• Materials used are very cost effective, typical parts cost under US$20
• A good variety of material is available including colour ABS and Medical ABS, investment casting wax and elastomer
• Mid range performance/cost RP system and is the best selling RP system in 1995

Disadvantages

• Accuracy is relatively low and is difficult to build parts with complicated details
• Poor strength in vertical direction
• Slow for building a mass part

Application Areas

• Conceptual modeling
• Fit, form and functional test
• Pattern for investment casting
• The MABS (methy methacrylate ABS) material is particularly suitable for medical applications